Paleohistory of the Larsen Ice Shelf: Evidence from the Marine Record

该奖项由极地项目办公室的南极地质和地球物理项目提供，支持对南极半岛拉森冰架最近占据的地区进行研究。在过去的10年里，科学家们观察到南极半岛北端的浮冰架急剧衰减和解体。气象记录和卫星观测表明，这种灾难性的衰退与过去50年来近3摄氏度的区域变暖有关。虽然浮冰架的这种退缩在历史记录中是前所未有的，但目前对过去几千年来冰架系统的自然变化的了解还不够充分。该奖项支持一个海洋地质研究项目，旨在通过了解全新世（过去1万年）期间北拉森冰架的动态来填补这一知识空白。拉森冰架位于威德尔海西北部，沿着南极半岛的东侧，在过去的五年里，卫星图像记录了它目前正在经历一个迅速的、灾难性的退缩。虽然南极半岛北部地区在过去40年中经历了明显的变暖趋势，但这种变暖与全球变化（即温室变暖）之间的联系并不明显。然而，冰架显然正在以历史上前所未有的速度后退，留下大片的海底裸露，并处于开阔的海洋环境中。该项目将在拉森入口和曾经被拉森冰架覆盖的地区收集一系列短沉积物岩心。通过将沉积物和化石标准应用于岩心，我们希望证明拉森冰架在过去一万年中是否经历了类似的退缩和随后的前进。过去在南极不同地区的工作主要集中在冰架的沉积模型上，这些模型使人们能够辨别罗斯海、南极半岛和普里兹湾地区冰架退缩/前进的时间。这项研究将大大提高对冰架系统动力学及其在过去和未来气候振荡中的作用的理解。

This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research to study the region recently occupied by the Larsen Ice Shelf in the Antarctic Peninsula. Over the last 10 years, scientists have observed a dramatic decay and disintegration of floating ice shelves along the northern end of the Antarctic Peninsula. Meteorological records and satellite observations indicate that this catastrophic decay is related to regional warming of nearly 3 degrees C in the last 50 years. While such retreat of floating ice shelves is unprecedented in historic records, current understanding of the natural variability of ice shelf systems over the last few thousand years is not understood well. This award supports a program of marine geologic research directed at filling this knowledge gap by developing an understanding of the dynamics of the northern Larsen Ice Shelf during the Holocene epoch (the last 10,000 years).The Larsen Ice Shelf is located in the NW Weddell Sea along the eastern side of the Antarctic Peninsula and is currently undergoing a rapid, catastrophic retreat as documented by satellite imagery over the past five years. While the region of the northern Antarctic Peninsula has experienced a pronounced warming trend over the last 40 years, the links between this warming and global change (i.e. greenhouse warming) are not obvious. Yet the ice shelf is clearly receding at a rate unprecedented in historic time, leaving vast areas of the seafloor uncovered and in an open marine setting. This project will collect a series of short sediment cores within the Larsen Inlet and in areas that were at one time covered by the Larsen Ice Shelf. By applying established sediment and fossil criteria to the cores we hope to demonstrate whether the Larsen Ice Shelf has experienced similar periods of retreat and subsequent advance within the last 10,000 years. Past work in various regions of the Antarctic has focused on depositional models for ice shelves that allow one to discern the timing of ice shelf retreat/advance in areas of the Ross Sea, Antarctic Peninsula, and Prydz Bay. This research will lead to a much improved understanding of the dynamics of ice shelf systems and their role in past and future climate oscillations.